Method for enhancing training effectiveness

ABSTRACT

The present invention provides methods for exercise training to improve exercise performance in an individual using low-resistance positive airway pressure and specialized gas mixtures during or immediately after exercise. The methods include wearing an interface, i.e. mask, connected by a tubing circuit to a positive airway pressure (PAP) assist ventilator device. The PAP device is connected to flexible tubing connected through a pressure regulator to a liquid gas source which supplies the gas mixture. The methods also include simulating high altitude exercise training by using the PAP device with a hypoxic level of oxygen in the gas mixture. The methods of the present invention reallocate oxygen between muscle groups, reduce fatigue, lessen episodes of dyspnea, improve conditioning levels and overall improve training to extreme levels of performance.

FIELD OF THE INVENTION

The present invention relates to exercise training and, in particular, a method for reallocating oxygen consumption load between various muscle groups in the human body to improve exercise effectiveness, more particularly through the use of, optionally multiple, oxygen load shifting strategies during the course of training to extreme exertion approaching the safe limits of human exertion and/or performance.

BACKGROUND OF THE INVENTION

Most commonly oxygen supplementation is used in medicine. Oxygen supplementation can employ helium and oxygen gas mixtures. For example, helium oxygen mixtures may be used in refractory asthma (status asthmaticus) and stridor. However, oxygen supplementation involving the use of pure oxygen is routinely used in sports, typically after an individual has undergone substantial physical exertion during a competitive event to hasten recovery after stress, for example, by a football player after running a touchdown. Research has also been done in the use of hypoxic atmospheres in training environments. Likewise, some scuba diving techniques may involve the breathing of helium and oxygen in the diving gas mixtures to reduce nitrogen narcosis, oxygen toxicity, and to allow greater dive depths and shorter decompression times.

SUMMARY OF THE INVENTION

In accordance with the invention, a person undergoing exercise training enhances exercise performance by reallocating the distribution of inspired oxygen, in order to optimize the amount of oxygen delivered to exercising muscles while decreasing the amount of oxygen used by respiratory muscles.

In accordance with the invention, it is recognized that the amount of oxygen absorbed by the lungs of a healthy individual during breathing is basically unaffected by the percentage of oxygen that is administered to an individual (or fraction of inspired oxygen) in the inhaled gas. Thus, the routine uses of oxygen in sports may be of little value. Reallocation of oxygen between muscle groups is the inventive approach. Healthy lungs deliver substantially the same amount of oxygen to body tissues whether the source of oxygen is air, which contains about 21% oxygen, or pure oxygen, that is, 100% oxygen. Therefore, increasing the fraction of inspired oxygen administered to an individual does not substantially affect how much oxygen is getting to the exercising muscles.

In accordance with the invention, it is recognized that what does affect the amount of oxygen delivered to exercising muscles is the density of air a person breaths while exercising: lower density oxygen-containing air is transported more easily through the airways to the gas-permeable cells, i.e. alveoli, of the lungs than higher density oxygen-containing air. One way to lower the density of oxygen-containing air is to mix helium gas with oxygen or oxygen-containing air. The use of a mixture of helium gas and oxygen gas (HeO₂), also referred to as heliox gas, has been reported to enhance the ability of noninvasive ventilation to reduce the effort of breathing and to improve gas exchange in patients suffering from chronic obstructive pulmonary disease (Jaber, S. et al., Noninvasive Ventilation with Helium-Oxygen in Acute Exacerbations of Chronic Obstructive Pulmonary Disease, Am. J. Respir. Crit. Care Med., Vol. 161, pp. 1191-1200, 2000). Hence, lowering the density of oxygen-containing air which an individual breaths during exercise training by using a mixture of HeO₂ gas, reduces the work expended by respiratory muscles, and thus more oxygen is available to the exercising muscles.

Positive end expiratory pressure (PEEP) recruits lung units that would not normally participate in ventilation so the lung is more efficient resulting in increased oxygen uptake by the lung, improved CO₂ clearance (bigger surface area for gas exchange). PEEP decreases airways resistance during exhalation and decreases dynamic airway collapse. A low density gas mixture reduces resistance during both inhalation and exhalation. Bilevel functionality (with higher inspiratory pressure) overcomes inspiratory resistance in the upper airways.

Currently, there exist a wide variety of noninvasive respiratory devices. See, for example, U.S. Patent Application No. 20069/0095300, which discloses a breathing apparatus comprised of a semi-closed breathing circuit which includes a gas reservoir into which some exhaled gas is directed and from which some inhaled gas is drawn wherein a portion of the gas reservoir is in fluid communication with an external environment. This device, however, does not provide for low resistance positive airway pressure ventilation to optimize the metabolism of exercising or recovering muscles.

The use of pure oxygen in sports to hasten recovery after exertion is of questionable value, and may actually be injurious, as prolonged use of a pure oxygen breathing gas can cause toxicity to the lungs. Moreover, such devices and their current techniques of use even do little or nothing to increase the effectiveness of recovery, despite their widespread use. A need exists, therefore, for a method to improve exercise training and performance by decreasing the work expended by respiratory muscles and increasing oxygen delivery to exercising muscles during and immediately after exercise training.

The present invention fulfills this need by providing methods of exercise training to improve exercise performance in an individual comprised of breathing a low-density gas comprised of a mixture of helium and oxygen (HeO₂) gas during and/or immediately after exercise training. The methods of the present invention are particularly well suited for healthy individuals who wish to improve their exercise performance during exercise.

In one aspect of the invention, there is provided a method of exercise training to improve exercise performance in an individual comprising breathing a low-density gas comprised of a mixture of HeO₂ gas by having an individual wear an interface which delivers the HeO₂ gas mixture to the individual. The interface is connected via a tubing circuit to a positive airway pressure (PAP) assist ventilator device which is connected to flexible tubing connected through a pressure regulator to a liquid gas source which supplies the HeO₂ gas mixture to the PAP device. Both the interface and the tubing circuit comprise a breathing circuit.

It is noted that the use of positive airway pressure is believed to be desirable in the context of the present invention, but that the invention contemplates training to the point of exertion, and preferably extreme exertion, using the inventive heliox mixture without such positive airway pressure. It is also noted that even if training is not to the point of extreme exertion, i.e. a submaximal level of exertion, the present invention will maximize the development of performance and the time necessary to achieve the corresponding level of muscle development in the targeted muscle group or groups.

In an embodiment, the individual breaths the mixture of HeO₂ gas during exercise training in order to reduce the work of breathing by the individual. In another embodiment, the individual breaths the mixture of HeO₂ gas immediately after exercise training to reduce recovery time from the exercise training and allow further training. In an embodiment, the individual breaths the mixture of HeO₂ gas during exercise training in order to reduce the work of breathing by the individual. In yet another most preferred embodiment, the individual breaths the mixture of HeO₂ gas during and immediately after exercise training to allow for extreme training.

In yet another most preferred embodiment, the individual breaths a hypoxic (fraction of inspired oxygen less than 21%) mixture of HeO₂ gas during and immediately after exercise training to both reduce recovery time from the exercise training, while allowing for higher performance, hypoxic exercise training. This method of exercise training increases the efficiency of body tissues at oxygen extraction from the circulatory system and can increase oxygen delivery to tissues by increasing the red blood cell mass, and altering the composition of the red blood cell, thus further enhancing performance during subsequent competitive activity. At 21% the viscosity of the oxygen is low enough to cause a minimal pulmonary muscle load, yet still provide enough oxygen to a normal person (who has not undergone hypoxic training) for training. Commercially, it may be most advantageous in non-hypoxic training regimens to maintain oxygen levels fairly close to 21, for example 20%-22%. Higher levels, approaching 24% to 28% or perhaps as much as 35% may be of value in certain circumstances such as with handicapped or other individuals suffering from impairments.

The inventive method of training an individual to improve performance in sports or other competitive activity by achieving a higher level of training for muscle groups associated with said competitive activity comprises having the individual breath a low-density gas mixture comprised of a mixture of helium and oxygen (HeO₂). The breathing of said low-density gas mixture is done while the individual is training. The training is performed to a point of exertion, optionally to a point reasonably approaching the limits of performance for the individual when it is desired to maximize the degree of muscle training. The viscous resistance associated with breathing the low-density gas mixture is low as compared with the viscous resistance associated with breathing air. The amount of oxygen consumed by the muscles involved with breathing is low as compared with consumption of oxygen of the muscles involved with breathing when the individual is breathing air. The oxygen available for exercising the muscles being trained is increased to provide increased development of the muscles being trained as compared with the development associated with training while breathing air.

More particularly, in this aspect of the invention, there is provided a method of simulating high altitude exercise training in an individual comprising breathing a low-density gas comprised of a mixture of helium gas and a hypoxic level of oxygen gas (He-hypO2) by having the individual wear an interface as described above which delivers the He-hypO₂ gas mixture to the individual. The interface is connected via a tubing circuit to a positive airway pressure (PAP) assist ventilator device as described above, which is connected to flexible tubing connected through a pressure regulator to a liquid gas source which supplies the He-hypO₂ gas mixture to the PAP device.

BRIEF DESCRIPTION OF THE DRAWING

A full understanding of the invention can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which:

FIG. 1 is an illustration of an individual breathing a mixture of HeO₂ gas or He-hypO₂ gas via an interface connected to a positive airway pressure (PAP) assist ventilator device according to the embodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides methods of training to improve athletic performance in an individual. More particularly, in accordance with the invention, the individual breaths a low-density gas comprised of a mixture of helium and oxygen (HeO₂) gas during and/or immediately after exercise training. The methods of the present invention are suited for healthy individuals who wish to improve their exercise performance during exercise training.

As used herein, except where defined otherwise, the phrase “exercising muscles” is meant to refer to those muscles involved in athletic training other than respiratory muscles required for breathing.

As used herein, the term “inspiration” is interchangeable with the term “inhalation;” the term “expiration” is interchangeable with the term “exhalation.”

In an embodiment of the present invention, as shown in FIG. 1, there is provided a method of exercise training to improve exercise performance in an individual 10 comprising breathing a low-density gas comprised of a mixture of helium and oxygen by having the individual 10 wear an interface 12 which delivers the HeO₂ gas mixture to the individual 10. The interface 12 is connected via a tubing circuit 14 to a positive airway pressure (PAP) assist ventilator device 16 which is connected to flexible tubing 18 connected through a pressure regulator 20 to a liquid gas source 22 which supplies the HeO₂ gas mixture to the PAP device 16. Both the interface 12 and the tubing circuit 14 comprise a breathing circuit 24.

In accordance with the invention, it has been recognized that during athletic training, and in particular competitive athletic training, the objective is to exercise certain muscle groups associated with the sport for which the individual is training. For example, in the case of track, the muscles of the legs and thighs and other associated muscle groups need to be developed to increase their performance. Performance development has as its objectives both the development of strength and endurance in the selected muscle groups.

In order for this to be achieved, these muscle groups have to perform at extreme levels of performance. Generally, normalizing for the body of the athlete, athletes who train to the point where their muscles are performing regularly at levels higher than their competitors will outperform competitors during a competition. In order to reach those higher levels of performance, the muscles must receive the raw materials which fueled the performance, namely, nutrition and oxygen, as well as clear out the toxic byproducts of metabolism, such as carbon dioxide. Nutrition regimens are well developed and are not the objective of the present invention. It is contemplated that conventional nutritional regimens may be employed with the inventive method.

However, the inventive method is concerned with techniques for increasing the amount of oxygen available during training to a muscle groups to be trained, as well as improving the clearance of metabolic byproducts, of these muscle groups, by the circulatory and respiratory systems More particularly, the invention contemplates the shifting of oxygen demand from muscles which are not the objective of a particular exercise to muscles which are the objective of the exercise, while at the same time improving clearance of metabolic byproducts that can limit exercise performance, accordingly allowing the user to achieve a higher workload during training, than is otherwise possible, resulting in more extreme development of the muscles which are the objective of the exercise.

In principle, an athlete in training may spend time pushing the extreme development and performance of a first group of muscles at one time, and pushing the extreme development and performance of another group of muscles at another time, thus bringing a large group for muscles to an extreme point of development and performance.

In accordance with the present invention, oxygen demand fulfillment is shifted from the muscles involved in breathing to other muscles by reducing the effort, or metabolic work, of breathing. This means that more oxygen is available and therefore exercise and training can be taken to a more extreme level of high performance. Generally, it is noted that the viscosity of air or other gaseous fluid being breathed by an individual is the cause of significant viscous resistance. This is because the air carrying passages of the lungs are extremely small at the ends of the airways where the blood is oxygenated. Because they are so small, very significant viscous resistance is encountered, forcing the muscles involved in breathing to do much work, and, and, consequently, consume much oxygen. In accordance with the invention, this load is reduced through the use of low viscosity breathing gases during exercising periods of extreme physical exertion, or during a period of recovery immediately after extreme physical exertion.

While the primary objective of the present invention is to use a low viscosity helium gas for the purpose of reducing oxygen demand by the muscles involved in breathing, in principle the invention also contemplates the use of a mask with small input air passages, valves, or other type of resistive loading device, which provides resistance to breathing, communicating with the ambient air in order to increase the amount of work needed to breathe, for the purpose of developing the muscles associated with breathing during a different part of the training regimen, which different part has the objective of increasing the performance of breathing muscles by pushing them to extremes not normally encountered during exercise. However, it is noted that depending upon the athletic event being trained for, enhanced performance of the lungs may not be an issue and such a part of the training regimen would not be necessary.

Finally, the possibility also exists to use a high viscosity breathing gas mixture during exercise, rest or a combination of both to increase the work being done by the muscles of the respiratory system.

Returning to the embodiment of the invention involving the reduction of the workload associated with breathing, the HeO₂ gas mixture provided in accordance with the present invention provides a fraction of inspired oxygen (FiO₂) of about 21% and a corresponding fraction of inspired helium (FiHe) of about 79%.

The interface 12 is comprised of a mask worn by the individual 10. The mask may be a full-face mask, a nasal style mask, an oro-nasal style mask, a mouth-only style mask, a high flow nasal cannula or any other style mask capable of delivering gas and/or pressure from the breathing circuit 24 to the individual 10. The mask or the tubing system may have a fixed or a variable leak function, or valve system in which the breathing circuit vents exhaled breath into the atmosphere. The system may also utilize cartridges of Lithium hydroxide, or other suitable carbon dioxide (CO₂) scavaging material in the mask, tubing or PAP device to further prevent the build up of exhaled CO₂ in the breathing circuit during exercise.

In accordance with the invention it is also contemplated that the mask may be battery powered or externally powered and/or may include a transmitter (either wired or wireless) for transmitting data between the mask and the PAP device 16.

The tubing circuit 14 may be made of a flexible, reinforced tube having adaptors (not shown) configured to fit into both the PAP device 16 and the interface 12. The tubing circuit 14 is gas impermeable and may contain internal wires for transmitting electrical power and/or data between the PAP device 16 and the interface 12.

In an embodiment, an individual 10 breaths the mixture of HeO₂ gas during exercise training in order to reduce the work of breathing by the individual 10. In another embodiment, an individual 10 breathes the mixture of HeO₂ gas at a pressures lightly greater than or equal to atmospheric pressure, immediately after exercise training to reduce recovery time from the exercise training or performance.

The liquid gas source 22 may be either an external high capacity liquid gas storage tank or a portable liquid gas canister.

The HeO₂ gas mixture gas may be delivered into the breathing circuit 24 in either a closed configuration or an open configuration. In the closed configuration, the HeO₂ gas mixture is supplied directly to the PAP device 16 via flexible tubing 18 connected to a liquid gas source 22. In an open configuration, the PAP device 16 draws air from the surrounding environment at ambient atmospheric pressure into the breathing circuit 24. The HeO₂ gas mixture may be delivered into the tubing circuit 14, into the interface 12, or into both the tubing circuit 14 and the interface 12.

The interface 12 or the tubing circuit 14 may contain an end tidal carbon dioxide (CO₂) sensor safety override system capable of measuring CO₂ levels in the breathing circuit 24. When unsafe levels of CO₂ are detected, the CO₂ sensor alters the PAP device 16 by altering system leak levels to allow for greater CO₂ escape from the breathing circuit 24, by changing pressure or flow levels, or by terminating function of the PAP device 16.

The PAP device 16 may contain an oxygen (O₂) sensor system capable of measuring the concentration of O₂ in the breathing circuit 24 and communicating this information to an electronics system onboard the PAP device 16.

The PAP device 16 may contain internal flow sensors and pressure sensors capable of sensing variable inspiratory rates, expiratory rates and leak rates within the breathing circuit 24.

The PAP device 16 may have an internal electronic algorithm which can vary the pressure delivered within the breathing circuit 24 in order to maintain a desired pressure.

The PAP device 16 is capable of generating either continuous level or bi-level modes of respiratory pressures within the breathing circuit 24. In a continuous mode, also referred to as continuous positive airway pressure (CPAP), the PAP device 16 generates a fixed respiratory pressure which ranges from about 4 cm to about 30 cm of H₂O pressure. In a bi-level mode, also referred to as bi-level positive airway pressure (BiPAP), the PAP device 16 generates a bi-level respiratory pressure in which the PAP device 16 cycles between a higher inspiratory pressure and a lower expiratory pressure. Both the inspiratory pressure and the expiratory pressure can range from about 4 cm to about 30 cm of H₂O pressure (with the inspiratory pressure having a higher value than the expiratory pressure).

The PAP device 16 may be powered by an internal or external power supply for use in an alternating current wall plug or in an internal or external battery pack power supply. In an embodiment, the PAP device 16 is powered by a portable battery power source and the liquid gas source 22 is a portable liquid gas canister, making the entire low-resistance positive airway system portable and wearable by an individual.

The PAP device 16 can contain internal software which provides wireless capability for wireless communication, device control and transfer of information from the PAP device 16.

In another aspect of the invention, also referring to FIG. 1, there is provided a method of simulating high altitude exercise training in an individual 10 comprising breathing a low-density gas comprised of a mixture of helium gas and a hypoxic level of oxygen gas (He-hypO₂) by having an individual 10 wear an interface 12 as described above which delivers the He-hypO₂ gas mixture to the individual 10. The interface 12 is connected via a tubing circuit 14 to a positive airway pressure (PAP) assist ventilator device 16 as described above, which is connected to flexible tubing 18 connected through a pressure regulator 20 to a liquid gas source 22 which supplies the He-hypO₂ gas mixture to the PAP device 16.

The He-hypO₂ gas mixture provides a FiO₂, for example, optionally ranging from about 16% to about 20% and a corresponding FiHe ranging from about 82% to about 80%.

The He-hypO₂ gas mixture gas may be delivered into the breathing circuit 24 in either a closed configuration or an open configuration. In the closed configuration, the He-hypO₂ gas mixture is supplied directly to the PAP device 16 via flexible tubing 18 which is connected to an external gas source 22 such as an external high capacity liquid gas storage tank. In an open configuration, the PAP device 16 draws air from the surrounding environment at ambient atmospheric pressure into the breathing circuit 24 and helium gas is delivered into the breathing circuit 24 to dilute the FiO₂. The helium gas can be delivered into the tubing circuit 14, the interface 12 or into both the tubing circuit 14 and the interface 12. The helium gas is delivered to the interface 12 via flexible tubing 18 connected to a liquid gas source 22 such as a liquid helium gas supply. The flow rate of the helium gas is controlled by an electronic pressure regulator 20 connected to the liquid helium gas supply via the flexible tubing 18. The pressure regulator 20 is controlled by an electronics system of the PAP device 16. The flow rate of the helium gas is varied according to an individual's minute ventilation rate. The flow rate of the helium gas may also be controlled by the oxygen sensor system, pressure sensors, flow sensors or safety sensors.

The PAP device 16 may contain a pulse oxymetry safety override system consisting of a pulse oxymeter probe (not shown) worn by the individual 10 during exercise training. The pulse oxymeter probe is capable of transmitting data either through wires or wirelessly from the oxymeter to the PAP device 16 electronics system in which a safety protocol is able to interrupt helium gas delivery to the interface 12 or alter PAP device 16 function if unsafe oxygen levels are detected in the individual 10.

The methods of the present invention improve exercise performance by reducing the work expended by respiratory muscles of the exercising individual. With reduced expenditure of energy by the respiratory muscles, the individual more efficiently clears CO₂ from the lungs produced by exercising muscles and body tissues and provides more O₂ to the exercising muscles and other body tissues. The overall effect is to reduce the work of breathing caused by elevated respiratory system workloads experienced with training for competitive activities. Thus, reducing the work of breathing during training using the methods of the present invention allows an individual to redirect metabolic energy from the respiratory muscles to the muscles of the individual which are undergoing training. This allows the individual to achieve higher performance levels due to increased metabolic efficiency. Regular use of the methods of the present invention during and optionally immediately after exercise training leads to more rapid and higher levels of physical conditioning than could be achieved with traditional exercise training methods.

At the same time, as alluded to above, in accordance with the invention, a positive airway pressure is used in feeding the helium/oxygen mixture to the individual undergoing training. This further reduces the oxygen load associated with breathing during extreme exercise training. Thus, the methods of the present invention reduce the work of breathing by an individual in two ways: breathing a HeO₂ gas mixture during or immediately after exercise training and the use of positive airway pressure during or immediately after exercise training, as discussed below.

A mixture of HeO₂ gas has a lower resistance through the airways of an individual as compared to atmospheric air. This is due to the substitution of helium gas for nitrogen gas normally found in atmospheric air. Helium gas has a lower density and viscosity, and thus a lower resistance through airway passages, than nitrogen gas. The low-resistance HeO₂ gas mixture thus reduces the viscosity associated with turbulent and non turbulent gas flow in large airway passages, at airway branch points and in irregularly-shaped upper airway passages of an individual. This in turn reduces the force required to generate a given inspiratory or expiratory flow rate by an individual.

The positive airway pressure used by the methods of the present invention provides a positive pressure assist to an individual during inhalation, which reduces the resistive work required to transport gas through the irregularly-shaped upper airway passages of an individual. The reduced work encountered by the individual allows the individual to generate higher tidal volumes with a smaller work load. The positive end expiratory pressure achieved by using positive airway pressure prevents dynamic airway collapse during forced exhalation which allows for more efficient clearance of exhaled gas during exercise training. The interface used in the methods of the present invention contains a leak system designed to use the positive pressure in the breathing circuit to wash exhaled CO₂ from an individual's dead space, but may also use a CO₂ scavenging material in the breathing circuit to achieve additional, or alternate CO₂ extraction capacity. This further improves the ventilatory efficiency of the individual's respiratory system. With the use of a low-resistance positive airway pressure system according to the methods of the present invention, an individual is able to improve the efficiency of their respiratory system by reducing the metabolic energy required to expel CO₂ and oxygenate body tissues, reduce dynamic expiratory collapse of the small airways, improve clearance of deadspace CO₂ in the upper airways, and as a result expel more CO₂ with each breath, which allows for lower respiratory rates and tidal volumes (further reducing the work of breathing) during and immediately after exercise training.

Thus, the methods of the present invention provide unexpected benefits to an individual that is undergoing exercise training or immediately recovering from exercise training such as (1) reduced work of breathing; (2) reduced fatigue levels; (3) less dyspnea (shortness of breath); (4) improved conditioning levels with repeated use compared to traditional exercise regimens; (5) improved recovery times after exercise; and (6) overall improved exercise performance.

If an, optionally hypoxic, mixture of helium and oxygen is used, the methods of the present invention provide the additional advantage of simulating altitude training and accordingly also provide unexpected benefits to an individual by easily simulating a high altitude, low O₂ environment at sea level (or at any altitude). This style of exercise will stimulate the bone marrow to produce a greater number of red blood cells allows. Red blood cell structure is also changed by this style of exercise, resulting in an increased concentration of 2,3 Bisphosphoglyceric acid (2,3, BPG.) This results in allowing the red blood cell to more efficiently deliver oxygen to the body tissues. Oxygen extraction by the body tissues is also improved by exposure to a hypoxic environment. These adaptations that allow an individual to effectively acclimate to exercise in a low O₂ environment, improve exercise results in normal oxygen environments

More importantly, such hypoxic conditioning, in accordance with the invention results in increasing the number of red blood cells, thus increasing the oxygen and CO₂ carrying capacity of the blood. This enables yet further extremes in training and conditioning resulting in further enhanced athletic performance. In accordance with the preferred embodiment, it is believed that the combination of hypoxic and low viscosity gases provides a multiple event which enables athletes to achieve extreme levels in the development of strength and endurance, and thus enable extreme performance.

Regular exposure to exercise in a hypoxic environment produces physiological changes in an individual which augments O₂ delivery, O₂ extraction from red blood cells and O₂ utilization in body tissues.

It is noted that in accordance with the present invention, training may be carried beyond conventional levels, and due to the same, increased performance can be achieved during athletic competition. In this regard, it is contemplated that trainers, as in conventional training regimens, generally push athletes to high levels of performance, taking care, of course, not to allow the athlete to engage in activity which might endanger the well-being of the person being trained.

The methods of the present invention, in addition to training for sports associated purposes such as competitive sports and mountaineering, may also be used by individuals in the military and in aerospace industries.

It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications that are within the spirit and scope of the invention, as defined by the appended claims. 

1. A method of training an individual to improve performance in sports or other competitive activity by achieving a higher level of training for muscle groups associated with said competitive activity, comprising having said individual breath a low-density gas mixture comprising helium and oxygen (HeO₂), said breathing of said low-density gas mixture being done while said individual is training, said training being performed to a point of exertion reasonably approaching the limits of performance for said individual; whereby the viscous resistance associated with breathing said low-density gas mixture is low as compared with the viscous resistance associated with breathing air, the amount of oxygen consumed by the muscles involved with breathing is low as compared with consumption of oxygen of said muscles involved with breathing when said individual is breathing air, and the oxygen available for exercising the muscles being trained is increased to provide increased development of the muscles being trained as compared with the development associated with breathing air while training.
 2. A method of training as in claim 1, wherein said gas mixture is delivered by a viscous circuit under a positive airway pressure.
 3. A method of training as in claim 1, wherein said individual wears an interface which delivers the low density gas mixture to the individual.
 4. A method of training as in claim 3, wherein said interface is connected via a tubing circuit to a low resistance positive airway pressure (PAP) assist ventilator device which is connected to flexible tubing connected through a pressure regulator to a liquid gas source that supplies the low-density gas mixture to the PAP device, wherein said interface and said tubing circuit comprises a breathing circuit.
 5. The method according to claim 1, wherein the individual is a healthy individual.
 6. The method according to claim 1, wherein the HeO₂ gas mixture provides a fractional inspired oxygen in the range between 14% to 60% and a corresponding fractional inspired helium in the range between 40 and 78%.
 7. The method according to claim 3, wherein the interface comprises a mask selected from the group consisting of a full-face mask, a nasal style mask, an oro-nasal style mask, a mouth-only style mask, a high flow nasal cannula and any other style mask capable of delivering gas and/or pressure from the breathing circuit to the individual, wherein said mask has a fixed or a variable leak function, wherein said mask optionally vents exhaled breath into the atmosphere through a resistance, wherein said mask optionally contains an adaptor capable of accepting power and/or transmitting data between the mask and the PAP device, and wherein said mask has the capability to accept a replaceable carbon dioxide absorbing material, either directly as a component of the mask, or supplied as part of an external cartridge attached to the mask directly, tubing system or PAP device.
 8. The method according to claim 1, wherein the tubing circuit consists of a flexible, reinforced tube having adaptors configured to fit into the PAP device and the interface, and wherein the tubing circuit is gas impermeable and optionally contains adaptors for external carbon dioxide absorbing material cartridges, internal wires for transmitting electrical power and/or data between the PAP device and the interface.
 9. The method according to claim 1, wherein the individual breaths the low-density gas mixture during exercise training to reduce the work of breathing by the individual, and immediately after exercise training to reduce recovery time from the exercise training.
 10. The method according to claim 9, wherein the low-density gas mixture is delivered into the breathing circuit in a closed configuration in which the low-density gas mixture is supplied directly to the PAP device via the flexible tubing connected to a gas source, or is delivered into the breathing circuit in an open configuration in which the PAP device draws air from the surrounding environment at ambient atmospheric pressure into the breathing circuit and the low-density gas mixture is delivered into the tubing circuit or into the interface or into both the tubing circuit and the interface, said HeO₂ gas mixture being delivered via flexible tubing connected to a liquid gas source.
 11. The method according to claim 1, wherein the liquid gas source is an external high capacity liquid gas storage tank or a liquid gas canister.
 12. The method according to claim 1, wherein the interface or the tubing circuit contains an end tidal carbon dioxide sensor safety override system capable of measuring carbon dioxide levels in the breathing circuit, wherein detection of unsafe levels of carbon dioxide levels alters the PAP device by altering system leak levels to allow for greater carbon dioxide escape from the breathing circuit, by changing pressure or flow levels, or by terminating function of the PAP device.
 13. The method according to claim 1, wherein the PAP device contains internal flow sensors and pressure sensors capable of sensing variable inspiratory rates, expiratory rates and leak rates within the breathing circuit, and wherein the PAP device has an internal electronic algorithm which varies the pressure delivered within the breathing circuit in order to maintain a desired pressure.
 14. The method according to claim 13, wherein the PAP device generates a continuous level fixed respiratory pressure ranging from about 4 cm to about 30 cm of H₂O pressure.
 15. The method according to claim 13, wherein the PAP device generates a bi-level respiratory pressure in which the PAP device cycles between a higher inspiratory pressure and a lower expiratory pressure, said inspiratory pressure and said expiratory pressure ranging from about 4 cm to about 30 cm of H₂O pressure.
 16. The method according to claim 1, wherein the PAP device is powered by a power source selected from the group consisting of an internal or external power supply for with in an alternating current wall plug and an internal or external battery pack power supply.
 17. A method of simulating high altitude exercise training in an individual comprising breathing a low-density gas comprised of a mixture of helium gas and a hypoxic level of oxygen gas (He-hypO₂) by having an individual wear an interface which delivers the He-hypO₂ gas mixture to the individual, said interface connected via a tubing circuit to a low resistance positive airway pressure (PAP) assist ventilator device which is connected via flexible tubing to a liquid gas source that supplies the He-hypO₂ gas mixture to the PAP device, wherein said interface and said tubing circuit comprises a breathing circuit.
 18. The method according to claim 15, wherein the He-hypO₂ gas mixture provides a FiO₂ ranging from about 14% to about 20% and a corresponding FiHe ranging from about 82% to about 80%.
 19. The method according to claim 15, wherein the PAP device contains an oxygen sensor system capable of measuring the concentration of oxygen in the breathing circuit and communicating this information to a control system of the PAP device.
 20. The method according to claim 15, wherein the He-hypO₂ is delivered into the breathing circuit in a closed configuration in which the He-hypO₂ gas mixture is supplied directly to the PAP device via the flexible tubing connected to an external high capacity liquid gas storage tank.
 21. The method according to claim 15, wherein the He-hypO₂ is delivered into the breathing circuit in an open configuration in which the PAP device draws air from the surrounding environment at ambient atmospheric pressure into the breathing circuit and helium gas is delivered into the breathing circuit to dilute the FiO₂, wherein the helium gas is delivered into the tubing circuit or into the interface or into both the tubing circuit and the interface, wherein the helium gas is delivered via flexible tubing connected to a liquid helium gas supply, wherein helium flow rate is controlled by an electronic pressure regulator connected to the liquid helium gas supply, said pressure regulator controlled by an electronics system of the PAP device, wherein the helium flow rate is varied according to the individual's minute ventilation rate and may also be controlled by the oxygen sensor system, pressure sensor, flow sensor or safety sensors.
 22. The method according to claim 15, wherein the PAP device contains a pulse oxymetry safety override system consisting of a pulse oxymeter probe which is worn by the individual during exercise training, said pulse oxymeter probe capable of transmitting data either wired or wirelessly from the oxymeter to the PAP device electronics system, wherein a safety protocol will interrupt helium delivery or alter PAP device function if unsafe oxygen levels are detected in the individual.
 23. A method of training an individual to improve performance in sports or other competitive activity by achieving a higher level of training for muscle groups associated with said competitive activity, comprising having said individual breath a low-density gas mixture comprising a mixture of helium and a hypoxic level of oxygen gas (He-hypO₂), said breathing of said low-density gas mixture being done while said individual is training; whereby the viscous resistance associated with breathing said low-density gas mixture is low as compared with the viscous resistance associated with breathing air, the amount of oxygen consumed by the muscles involved with breathing is low as compared with consumption of oxygen of said muscles involved with breathing when said individual is breathing air, and the oxygen available for exercising the muscles being trained is increased to provide increased development of the muscles being trained as compared with the development associated with breathing air while training.
 24. A method of training as in claim 23, wherein said gas mixture is delivered by a viscous circuit under a positive airway pressure.
 25. A method of training as in claim 1, wherein the method is used to train different muscle groups at different times.
 26. A method as in claim 1 further comprising training with the lungs to an extreme level of performance by increasing the workload associated with breathing by providing high viscous resistance passages for inhalation by the individual undergoing training.
 27. A method as in claim 26 wherein the low density gas mixture is a hypoxic mixture comprising helium and oxygen.
 28. A method as in claim 23, wherein said training is performed to a point of exertion reasonably approaching the limits of performance for said individual. 